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Spectrochimica acta. Part A: Molecular spectroscopy最新文献

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Excitation wavelength and solvent dependent emission spectra in weakly polar aprotic solvents at room temperature and 77 K 弱极性非质子溶剂在室温和77 K下的激发波长和溶剂依赖的发射光谱
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)80096-0
Sivaprasad Mitra, Ranjan Das, Samaresh Mukherjee
{"title":"Excitation wavelength and solvent dependent emission spectra in weakly polar aprotic solvents at room temperature and 77 K","authors":"Sivaprasad Mitra,&nbsp;Ranjan Das,&nbsp;Samaresh Mukherjee","doi":"10.1016/0584-8539(94)80096-0","DOIUrl":"10.1016/0584-8539(94)80096-0","url":null,"abstract":"<div><p>Excitation wavelength-dependent emission spectra of 4-methyl-2,6-diformylphenol (MFOH) and <em>o</em>-hydroxybenzaldehyde (OHBA) have been examined both in pure weakly polar aprotic solvents and in the presence of a base at room temperature and 77 K. It is shown that fluorescence quantum yield shape, position of the spectra, and number of conformers are dependent upon the excitation energy and also on the proton-accepting ability of the solvents. Fluorescence spectra cannot be correlated with the solvent dielectric properties. At 77 K, deactivation occurs via phosphorescence only at a particular experimental condition in all the solvents studied here. The decay rates are relatively slower in an environment where the probability of hydrogen bonding interaction is stronger.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 7","pages":"Pages 1301-1308"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)80096-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82328511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 14
FTIR spectra of the 2ν4, ν4 + ν6 and 2ν6 bands of formaldehyde 甲醛的2ν4， ν4 + ν6和2ν6波段的FTIR光谱
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)E0050-K
Fumiyuki Ito, Taisuke Nakanaga, Harutoshi Takeo
{"title":"FTIR spectra of the 2ν4, ν4 + ν6 and 2ν6 bands of formaldehyde","authors":"Fumiyuki Ito,&nbsp;Taisuke Nakanaga,&nbsp;Harutoshi Takeo","doi":"10.1016/0584-8539(94)E0050-K","DOIUrl":"10.1016/0584-8539(94)E0050-K","url":null,"abstract":"<div><p>High resolution IR spectra of the overtones and the combination band of the ν<sub>4</sub> and ν<sub>6</sub> modes of formaldehyde (2ν<sub>4</sub>, ν<sub>4</sub> + ν<sub>6</sub> and 2ν<sub>6</sub>) were measured in the region of 2200–2650 cm<sup>−1</sup> using FTIR. The combination band ν<sub>4</sub> + ν<sub>6</sub>, whose dipole transition is forbidden from molecular symmetry, was observed due to the intensity borrowed from the other bands. The observed frequencies were analysed by a Hamiltonian in which <em>A</em>-type Coriolis interactions and Darling—Dennison interaction were taken into account. The ratio and the relative signs of the transition dipole moments of the overtone bands, μ<sub>2ν4</sub> and μ<sub>2ν6</sub>, have been determined by analysing the intensity distribution of the vibration—rotation lines.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 8","pages":"Pages 1397-1412"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)E0050-K","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89924144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 17
FT-NIR atlas FT-NIR阿特拉斯
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)80102-9
B.G. Osborne
{"title":"FT-NIR atlas","authors":"B.G. Osborne","doi":"10.1016/0584-8539(94)80102-9","DOIUrl":"10.1016/0584-8539(94)80102-9","url":null,"abstract":"","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 7","pages":"Pages 1341-1342"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)80102-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86562612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Effect of thickness and monolayer location on thermostability of metal stearate LB films studied by FT-IR reflection—absorption spectroscopy 用FT-IR反射吸收光谱法研究了硬脂酸盐LB金属薄膜厚度和单层位置对热稳定性的影响
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)E0067-K
J. Umemura, S. Takeda , T. Hasegawa , T. Kamata , T. Takenaka
{"title":"Effect of thickness and monolayer location on thermostability of metal stearate LB films studied by FT-IR reflection—absorption spectroscopy","authors":"J. Umemura,&nbsp;S. Takeda ,&nbsp;T. Hasegawa ,&nbsp;T. Kamata ,&nbsp;T. Takenaka","doi":"10.1016/0584-8539(94)E0067-K","DOIUrl":"10.1016/0584-8539(94)E0067-K","url":null,"abstract":"<div><p>LB films of Cd and Ca stearates with 1, 3, 9, and 21 monolayers were fabricated on silver-coated glass slides. 9-Monolayer LB films of Cd and Ca salts of deuterated stearic acid, in which the 1st, 5th, or 9th layer was replaced by 1 monolayer of undeuterated analogues, were also prepared on the above substrates. Temperature dependences of Fourier transform infrared (FT-IR) reflection—absorption (RA) spectra were examined for these LB films in the range 31–140°C. At room temperature, the hydrocarbon chains in these LB films were in a well-ordered state with a high degree of perpendicular orientation to the substrate. However, they became disordered at elevated temperatures. These order-disorder phase transition temperatures were dependent on the film thickness, to a small degree in the Cd stearate LB film (102–108°C), but to a large degree in the Ca stearate LB film (103–129°C). In the latter LB film, the effect of dehydration was inferred. The degree of disorder at high temperatures was dependent on the film thickness and the location of monolayer in the 9-monolayer LB films. This result is discussed in terms of the internal pressure within the LB film.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 8","pages":"Pages 1563-1571"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)E0067-K","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83874388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
Polarised single crystal Raman spectroscopy of sinhalite, MgAlBO4 僧帽石MgAlBO4的偏振单晶拉曼光谱
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)80094-4
Chris L. Hayward , Stephen P. Best , Robin J.H. Clark , Nancy L. Ross , Rob Withnall
{"title":"Polarised single crystal Raman spectroscopy of sinhalite, MgAlBO4","authors":"Chris L. Hayward ,&nbsp;Stephen P. Best ,&nbsp;Robin J.H. Clark ,&nbsp;Nancy L. Ross ,&nbsp;Rob Withnall","doi":"10.1016/0584-8539(94)80094-4","DOIUrl":"10.1016/0584-8539(94)80094-4","url":null,"abstract":"<div><p>Polarised single-crystal Raman spectra for sinhalite have been collected at 80 K over the range 1300-10 cm<sup>−1</sup>. All 36 of the first-order Raman bands predicted by the factor group analysis (FGA) of the olivine structure type have been observed and assigned. Sinhalite has the smallest unit cell volume of any crystal with the olivine structure and is significantly more distorted than are the silicate olivines. This leads to distortion-related consequences in the vibrational spectra, such as greater wavenumber ranges for each type of mode and reduced Raman intensity for symmetric BO<sub>4</sub> modes. Intense Raman bands in the region 796-468 cm<sup>−1</sup> are assigned to BO<sub>4</sub> rotations/translations which deform the AlO bond without displacement of the aluminium atoms which lie on the M1 sites. Raman-active modes involving M1 cation displacements are incompatible with the FGA.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 7","pages":"Pages 1287-1294"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)80094-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87318961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
List of special issues 特刊一览表
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)80079-0
{"title":"List of special issues","authors":"","doi":"10.1016/0584-8539(94)80079-0","DOIUrl":"https://doi.org/10.1016/0584-8539(94)80079-0","url":null,"abstract":"","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 8","pages":"Page I"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)80079-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137349253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
ESR characterisation of SO−3 and SO−4 radicals in X-irradiated kainite (KMgClSO4.3H2O) x射线照射的KMgClSO4.3H2O中SO−3和SO−4自由基的ESR表征
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)80097-9
M. Salagram, K. Madhukar , T.S.N. Murthy , C.S. Sunandana
{"title":"ESR characterisation of SO−3 and SO−4 radicals in X-irradiated kainite (KMgClSO4.3H2O)","authors":"M. Salagram,&nbsp;K. Madhukar ,&nbsp;T.S.N. Murthy ,&nbsp;C.S. Sunandana","doi":"10.1016/0584-8539(94)80097-9","DOIUrl":"10.1016/0584-8539(94)80097-9","url":null,"abstract":"<div><p>The ESR spectra of the kainite (KMgClSO<sub>4</sub>.3H<sub>2</sub>O) crystal revealed an intense isotropic (<em>g</em> = 2.004) peak C attributed to the SO<sup>−</sup><sub>3</sub> radical and two pairs of lines (A<sub>1</sub>, A<sub>2</sub>) and (B<sub>1</sub>, B<sub>2</sub>) bearing intensity ratio 5:3. The intensity and linewidth variation of peak C suggested that the signal contains an unresolved shf structure. The power saturation studies on SO<sup>−</sup><sub>3</sub> indicate that its ESR line is homogeneously broadened and its line shape is Lorentzian. The spin—lattice and spin—spin relaxation times (<em>T</em><sub>1</sub> and <em>T</em><sub>2</sub>) of SO<sup>−</sup><sub>3</sub> have been estimated to be 0.44 s and 656 μs, respectively. The analysis of the anisotropic pairs of lines show that they constitute two sets A and B and are due to two chemically inequivalent SO<sup>−</sup><sub>4</sub> radical species in the lattice. The ESR spectra of the polycrystalline samples recorded at 300 and 77 K confirm the isotropic behaviour of SO<sup>−</sup><sub>3</sub> and chemical inequivalence of two types of SO<sup>−</sup><sub>4</sub> radicals. The principal <em>g</em>-values of the SO<sup>−</sup><sub>4</sub> radical were evaluated to be: <em>g</em><sub>1</sub> = 2.007, <em>g</em><sub>2</sub> = 2.011, <em>g</em><sub>3</sub> = 2.014 for species A and <em>g</em><sub>1</sub> = 2.008, <em>g</em><sub>2</sub> = 2.012, <em>g</em><sub>3</sub> = 2.015 for species B. The low microsymmetry of the SO<sup>2−</sup><sub>4</sub> ion in the lattice seems to promote the radiation damage.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 7","pages":"Pages 1309-1315"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)80097-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81616205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
A multi-reflection Raman cell for studying dilute aqueous solutions 用于稀水溶液研究的多反射拉曼电池
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)E0062-F
K. Kamogawa , M. Takamura , H. Matsuura , T. Kitagawa
{"title":"A multi-reflection Raman cell for studying dilute aqueous solutions","authors":"K. Kamogawa ,&nbsp;M. Takamura ,&nbsp;H. Matsuura ,&nbsp;T. Kitagawa","doi":"10.1016/0584-8539(94)E0062-F","DOIUrl":"10.1016/0584-8539(94)E0062-F","url":null,"abstract":"<div><p>A cell for multi-reflection Raman measurements was constructed. This device consists of two rectangular prisms and, when applied to a rectangular sample cell, Raman signals were enhanced by seven to ten times compared with the single-pass measurement for a transparent solution. This system is readily applicable to studies of dilute aqueous solutions with low refractive indices. With this device, the CH stretching Raman bands of benzene in water were observed with sufficiently high S/N ratios. Combination of the multi-pass cell with an optical-fiber light-collecting device enabled us to determine reproducibly the shifts of Raman bands from some reference state with an accuracy of 0.006 cm<sup>−1</sup>.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 8","pages":"Pages 1513-1519"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)E0062-F","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86408642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Raman spectra and structure of biphenyl isoatomers (the S0, S1, T1 states and the cation and anion radicals) 联苯等原子体的拉曼光谱和结构(S0、S1、T1态和正阴离子自由基)
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)E0058-I
Yutaka Sasaki , Hiro-o Hamaguchi
{"title":"Raman spectra and structure of biphenyl isoatomers (the S0, S1, T1 states and the cation and anion radicals)","authors":"Yutaka Sasaki ,&nbsp;Hiro-o Hamaguchi","doi":"10.1016/0584-8539(94)E0058-I","DOIUrl":"10.1016/0584-8539(94)E0058-I","url":null,"abstract":"<div><p>The Raman and transient resonance Raman spectra of biphenyl (BP) and its perdeuterated analogue (BP-<em>d</em><sub>10</sub>) in three different electronic states (<em>S</em><sub>0</sub>, <em>S</em><sub>1</sub> and <em>T</em><sub>1</sub>) and in two different ionized states (cation and anion) have been recorded in solution. The <em>S</em><sub>0</sub> Raman spectra have also been measured for the crystalline state. The obtained set of spectra are analysed on the basis of the established vibrational assignments for the ground state of the planar (crystal) and the non-planar (solution) structures. The analysis suggests that BP in solution exists as a twisted structure in the <em>S</em><sub>1</sub> state, but that it takes planar or nearly planar structures in the <em>T</em><sub>1</sub>, the cationic and the anionic states.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 8","pages":"Pages 1475-1485"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)E0058-I","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78405071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 33
Quantitative analysis of emulsions using attenuated total reflectance (ATR) 利用衰减全反射(ATR)定量分析乳剂
Spectrochimica acta. Part A: Molecular spectroscopy Pub Date : 1994-07-01 DOI: 10.1016/0584-8539(94)80088-X
E.K. Kemsley, G.P. Appleton, R.H. Wilson
{"title":"Quantitative analysis of emulsions using attenuated total reflectance (ATR)","authors":"E.K. Kemsley,&nbsp;G.P. Appleton,&nbsp;R.H. Wilson","doi":"10.1016/0584-8539(94)80088-X","DOIUrl":"10.1016/0584-8539(94)80088-X","url":null,"abstract":"<div><p>Quantitative analysis using attenuated total reflectance (ATR) is increasingly being applied to food materials, including many heterogeneous materials such as dairy produce. In this work, a non-linear calibration for the fat content of cream is disclosed. A theory to explain these results has been developed, and is supported by experimental evidence obtained from a model system of latex beads.</p></div>","PeriodicalId":82782,"journal":{"name":"Spectrochimica acta. Part A: Molecular spectroscopy","volume":"50 7","pages":"Pages 1235-1242"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0584-8539(94)80088-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88735729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
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